Glass bottles are formed in an I.S. machine in a two step process. First a gob of molten glass is formed into a “parison” in a blank station. The skin of the parison is chilled to give the parison sufficient rigidity so that in can be transferred, by an invert mechanism to the blow station. At the blow station blow molds will be closed and the parison will be blown into a bottle. The skin of the bottle will be chilled sufficiently so that it can be transferred to a dead plate by a take out mechanism. At the dead plate, the bottles will be further cooled and then pushed onto a conveyor by a pusher mechanism. Each of these displacements may have very difficult segments where very small variations may have significant importance.
For example, when bottles are being produced at more than 600 per minute on an I.S. Machine, it is very difficult to coordinate the placement of the bottles on the conveyor without causing the bottles to fall. Bottles are deposited on a dead plate, where they will be cooled for short period of time, and then pushed by a pusher mechanism (pusher) through an angle of about 90 degrees onto a moving conveyor. The pusher has a finger assembly which defines a pocket for each of the bottles deposited on the deadplate. The finger assembly is located on the deadplate before the bottles are deposited. A pair of servo motors displaces the pusher pursuant to defined cam profiles and numerous cams are stored in memory to handle a variety of bottles and machine speeds. To vary such displacement, a cam profile will be changed. As the speed of these machines increases, the difficulty involved in controlling the bottles, as they are displaced, increases. One of the most difficult segments of pusher displacement is the displacement of the bottles onto the conveyor and the immediate displacement of the pusher away from the conveyor once the bottles have been properly positioned on the conveyor.